It is proposed that 4 novel therapies and 2 diagnostics be evaluated. Regeneration. The potential for stimulation of periodontal regeneration with application of the polypeptide growth factors will be tested in patients who have successfully completed periodontal therapy but have residual infrabony pockets. PDGF (platelet derived growth factor) and IGF (insulin derived growth factor) will be topically applied to the tooth root and alveolar defect. The response will be evaluated by a split-mouth comparison with application of the vehicle alone. Immunomodulators. Proof of principle studies will be conducted by "piggy- back" analysis of two placebo controlled studies in which patients with systemic disease are being treated by new types of therapy. This includes an investigation of patients who are being treated with the IL-1 receptor antagonist ANTRIL to relieve rheumatoid arthritis and a second group of patients being treated by the neutrophil stimulating carbohydrate. Betafectin for bone marrow failure. In each case, a subpopulation with coincident periodontal disease will be identified and clinical measures of change following therapy evaluated. In addition, animal studies are planned to examine the effect of these agents in model systems. Antibody Response to Scaling. The antibody response to scaling will be investigated in two types of tests. One study is designed to determine if clinical and microbiological effects associated with humoral antibody changes can be measured when sites are scaled elsewhere in the mouth. A second study is designed to determine if extensive scaling or disease active sites can be used to augment therapeutic and/or microbiologic response. Antibody Response to Scaling. The antibody response to scaling will be investigated in two types of tests. One study is designed to determine if clinical and microbiological effects associated with humoral antibody changes can be measured when sites are scaled elsewhere in the mouth. A second study is designed to determine if extensive scaling of disease active sites can be used to augment therapeutic and/or microbiologic response. Diagnostic. Electrical impedance of the periodontal pocket will be investigated in conjunction with the testing of an electronic pocket depth probe to determine potential utility in detecting conditions of pocket ulceration. Computer algorithms will be written and tested to develop methods to obtain quantitative information on periodontal bone loss by radiographic subtraction techniques under conditions of minimal standardization such as would occur in routine clinical practice.